Porcine Reproducive and Respiratory Syndrome (PRRS) and secondary co-infections: New aspects, economic impact and update situation in Greece


V. G. PAPATSIROS (Β.Γ. ΠΑΠΑΤΣΙΡΟΣ)
C. ALEXOPOULOS (Κ. ΑΛΕΞΟΠΟΥΛΟΣ)
S. C. KYRIAKIS (Σ.Κ. ΚΥΡΙΑΚΗΣ)
Abstract

The clinical manifestations of PRRS virus infection vary from subclinical to severe reproductive failure and/or respiratory disease. Severity of PRRS virus associated disease may result from interactions among factors involving differences in virulence among PRRS virus isolates, probable recombination between the different isolates that are responsible for the clinical manifestation of PRRS in the same farm, differences in concurrent infections (other viruses and bacteria) and hygiene monitoring programme. It is known that viruses and bacteria interacted and the most common model of this interaction is that pathogens bacteria complicate the lesions that are due to viruses. PRRS virus induces predisposition to Streptococcus suis in nursery age pigs and increases susceptibility to Salmonella choleraesuis, Bordetella bronchiseptica and Mycoplasma hyopneumoniae. Furthermore, PRRS virus is involved in aetiology and predispose to appearance of Porcine Respiratory Disease Complex (PRDC) Postweaning Multisystemic Wasting Syndrome (PMWS) and Porcine Dermatitis and Nephropathy Syndrome (PDNS). The respiratory form of PRRS co-infection with Aujeszky' disease causes severe losses in swine herds due to respiratory problems. In cases of PRRS co-infections with other agents, the cost of pork meat production is raised from the treatments and other special management strategies. Up to date, in Greece, PRRS is appeared with the enzootic form (independendy of the season) with elevations and declines. In Greek swine industry, PRRS virus is involved as primary pathogen agent in cautions of mortality of growing/finishing pigs. During the last years, the presence of the new syndromes of PRDC, PMWS and PDNS causes additional economical losses and increases the cost of Greek pork meat production. The unpublished data of editors indicate that during last year, PRRS caused severe losses in Greek swine industry. Cases of PRRS were noticed in farms which purchased gilts or piglets without keeping out preventive facilities of biosecurity as quarantine, serology examinations etc. The syndrome was appeared with the respiratory form in growing/finishing pigs associated with severe losses, due to the entrance of «new» different isolates of PRRS virus from the purchase of gilts or piglets. It is probably that these «new» different isolates were more virulent than the preexisted isolates or/and predominated with them. In cases, where severe respiratory signs in growing/finishing pigs and no or moderate reproductive form of PRRS were noticed, it is probable that the vaccinations of sows against PRRS did not protect the growing/finishing pigs or the «new» different isolates of PRRS virus had more respiratory than reproductive tropism or coexistenced in all earlier circumstances. Today, PRRS is a dangerous risk factor for the Greek swine industry and for this reason it is important to apply all preventive facilities as: vaccinations, reduction of the introduction gilts and maintenance of a grandparent nucleus in the farm for producing gilts, quarantine and serological monitoring for all introduced animals (gilts and piglets), as well as the purchase of animals from PRRS-negative farms. The purchase of piglets has to be avoided because it induces negative effects on the clinical manifestation and control of PRRS.

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Literaturhinweise
Albina Ε, Kobish M, Cariolet R, Keranflec H, Beaurepaire B, Hutet E, Labbe A. (1995). Le syndrome dysgenesique et respiratoire du porc (SDRP): etude expérimentale des effects de l'infection sur la response immunitaire et la resistance aux infections Aujeszky et Mycoplasma hyopneumoniae chez le porc en croissance. J Rech Porcine France, 27:107-116.
Albina E, Piriou L, Hutet E, Cariolet R, L'Hospitalier R. (1998). Immune responses in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV). Vet Immunol Immunopathol, 61: 49-66.
Alexopoulos C, Kritas SK, Kyriakis CS, Tzika E, Kyriakis SC (2005). Sow performance in an endemically porcine reproductive and respiratory syndrome (PRRS)-infected farm after sow vaccination with an attenuated PRRS vaccine. Vet Microbiol, 111: 151-157.
Allan GM, McNeilly F, Ellis J, Krakowka S, Meehan B, McNair I, Walker I, Kenned S. (2000). Experimental infection of colostrums deprived piglets with porcine circovirus 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) potentiates PCV2 replication. Arch Virol, 145: 2421-2429.
Allende R, Lewis TL, Lu Ζ, Rock DL, Kutish GF, Ali A, Doster AR, Osorio FA. (1999). North American and European porcine reproductive and respiratory syndrome viruses differ in nonstructural protein coding regions. J Gen Virol, 80: 307-315.
Allende R, Kutish GF, Laegreid W, Lu Ζ, Lewis TL, Rock DL, Friesen J, Galeota JA, Doster AR, Osorio FA. (2000). Mutations in the genome of porcine reproductive and respiratory syndrome
virus responsible for the attenuation phenotype. Arch Virol, 145: 1149-1161.
Andreyev VG, Wesley RD, Mengeling WL, Vorwald AC, Lager KM. (1997). Genetic variation and phylogenetic relationships of 22 porcine reproductive and respiratory syndrome virus (PRRSV) field strains based on sequence analysis of open reading frame 5. Arch Virol, 142: 993-1001.
Balkamos GC, Kyriakis SC, Saoulidis K, Sarris Kr, Batsios Ch, Alexopoulos C, Spais A. (2002). Causes of death in growing and finishing pigs on farrow-to-finish industrial farms in Greece: II.
The impact of respiratory and digestive diseases. In: Proceedings of the 17th International Pig Veterinary Society Congress, Ames, Iowa, USA, vol. 2: 287.
Balkamos GC. (2004). Causes of death in growing - finishing pigs on industrial pig farms in Greece. Doctoral Thesis. Faculty of Veterinary Medicine, Aristotle University of Thessaloniki,
Thessaloniki.
Batista L, Pijoan C, Torremorell M. (2002). Experimental injection of gilts with porcine reproductive and respiratory syndrome virus (PRRSV) during acclimatization. J Swine Health Prod: 147-152.
Bell A. (1998). Hot PRRS is still hot. Pork (February): 32-33.
Benfield DA, Nelson E,Collins JE, Harris L, Goyal SM, Bobinson D, Christianson WT, Morrison RB, Gorcyca D and Chladek D. (1992). Characterization of swine infertility and respiratory syndrome (SIRS) virus (isolate ATCC VR-2332). J Vet Diagn Invest, 4: 127-133.
Benfield DA, Collins JE, Dee SA, Halbur PG, Joo HS, Lager KM, Mengeling WL, Murtaugh MP, Rossow KD, Stevenson GW, Zimmerman J J. (1999). Porcine reproductive and respiratory syndrome. In: Diseases of Swine (8th ed). Straw BE, DAllaire S, Mengeling WL, Taylor DJ (eds), Ames, Iowa, Iowa State University Press: 201-232.
Bierk MD, Dee SA, Rossow KD, Otake S, Collins JE, Molitor TW. (2001). Diagnostic investigation of chronic porcine reproductive and respiratory syndrome virus in a breeding herd of pigs. Vet Ree, 148: 687-690.
Blackburn PW (1991). PRRS-The impact of the disease on the pig industry-the experience of veterinary practice in the U. K. European Commision Seminar on PRRS. 11/4-5, 1991. Brussels: 15.
Blaha T. (1992). Epidemiological investigations into PEARS in Germany: Consequences in fattening pigs. In: Proceedings of the 12th International Pig Veterinary Society Congress, The Hague, The Netherlands: 126.
Blaha T. (2000). The "colorful" epidemiology of PRRS. Vet Res, 31:71-83.
Botner A, Strandbygaard B, Sorensen KJ, Have P, Madsen KG, Madsen S and Alexandersen S. (1997). Appearance of acute PRRS-like symptoms in sow herds after vaccination with a modified live PRRS vaccine. Vet Ree, 141: 497-499.
Botner A, Nielsen J, Oleksiewicz MB, Storgaard T. (1999). Heterologous challenge with porcine reproductive and respiratory syndrome (PRRS) vaccine virus: no evidence of reactivation of previous European-type PRRS virus infection. Vet Microbiol, 68: 187-195.
Brockmeier SL, Palmer MV, Bolin SR. (2000). Effects of intranasal inoculation of porcine reproductive and respiratory syndrome virus, Bordetella bronchiseptica or combination of boh organisms in pigs. Am J Vet Res, 61: 892-899.
Carvalho I, Segales J, and Pijoan C (1995). Effect of PRRSV on subsequent Pasteurella multocida challenge in pigs. In: Proceedings of the 2nd International Symposium on Porcine Reproductive and Respiratory Syndrome, Copenhagen, Denmark: 20.
Carvalho LFOS, Segales J, Pijoan C. (1997). Effect of porcine reproductive and respiratory syndrome virus on subsequent Pasteurella multocida challenge in pigs. Vet Microbiol, 55: 241-
Cavanagh D. (1997). Nidovirales: A new order comprising Coronaviridae and Arterividae. Arch Virol, 142 (3): 629-633.
Choi C and Chae C. (2001). Colocalization of porcine reproductive and respiratory syndrome virus and porcine circovirus 2 in porcine dermatitis and nephrology syndrome by double-labelling
technique. Vet Pathol, 38(4): 436-41.
Christopher-Hennings J, Holler LD, Benfield DA, Nelson EA. (2001). Detection and duration of porcine reproductive and respiratory syndrome virus in semen, serum, periphereal blood mononuclear cells and tissues from Yorkshire, Hampshire and Landrace boars. J Vet Diagn Invest, 13: 133-142.
Clark LK. (1996) Mycoplasmal pneumonia-an emerging disease. In: Proceedings of Swine Disease Conference for Swine Practitioners, Iowa State University: 63-66.
Collins JE, Benfield DA, Christianson WT, Harris L, Hennings JC, Shaw DP, Goyal SM, McCullough S, Morrison RB and Joo HS. (1992). Isolation of swine infertility and respiratory syndrome virus (isolate ATCC VR-2332) in North America and experimental reproduction of the disease in gnotobiotic pigs. J Vet Diagn Invest, 4: 117-126.
Collins JE, Rossow KD. (1993). Pathogenesis of PRRS. In: Proceedings of the Allen D. Leman Swine Conference, University of Minnesota, USA: 47-48.
Conzelman KK, Visser Ν, Van Woensel Ρ and Thiel NJ. (1993). Molecular characterization of porcine reproductive and respiratory syndrome virus, a member of the arterivirus group. Virology, 193: 329-339.
Cooper VL, Doster AR, Hesse RA, Harris NB. (1995). Porcine reproductive and respiratory syndrome: NEB-1 PRRSV infection did not potentiate bacterial pathogens. J Vet Diagn Invest, 7: 313-320.
Dea S, Gagnon GA, Mardassi H, Pirzadeh B, Rogan D. (2000). Current knowledge on the structural proteins of porcine reproductive and respiratory syndrome (PRRS) virus: comparison of the North American and European isolates. Arch Virol, 145: 659-688.
Dee SA, Morrison RB, Joo HS. (1993). Eradicating porcine reproductive and respiratory syndrome (PRRS) virus using two site production and nursery depopulation. J Swine Health Prod,
: 20-23.
Dee SA, Joo HS. (1994). Prevention of the spread of porcine reproductive and respiratory syndrome virus in endemically infected pig herds by nursery depopulation. Vet Ree, 135: 6-9.
Dee SA. (1996). The porcine respiratory disease complex: Are subpopulations important? J Swine Health Prod, 4 (3): 147-149.
Dee SA, Joo HS, Henry S, Tokach L, Park BK, Molitor TW, and Pijoan C. (1996). Detecting subpopulations after PRRS virus infection in large breeding herds using multiple serologic tests.
J Swine Health Prod, 4(4): 181-184.
Dee SA, Joo HS, Poison DD and Marsh WE. (1997a). Evaluation of the effects of nursery depopulation on the persistence of PRRS virus and the reproductivity of 34 pig farms. Vet Ree, 140: 247-248.
Dee SA, Joo HS, Poison DD, Park BK, Pijoan C, Molitor TW, Collins JE and King V. (1997b). An evaluation of nursery depopulation on 34 pig farms: Effect on PRRS virus persistence and productivity. Vet Ree, 140: 498-500.
Dee SA, Torremorell M, Rossow K, Mahlum C, Otake S, Faaberg K. (2001). Identification of genetically diverse sequences (ORF 5) of porcine reproductive and respiratory syndrome virus in a
swine herd. Can J Vet Res, 65:254-260.
Dee S. (2004). The science of PRRS: What do we really know about its transmission, diagnosis and control? In: Proceedings of the 35th Annual Meeting of American Association of Swine Veterinarians, Des Moines Marriott, Des Moines, Iowa: 353-358.
Desrosiers R. (1998) Control of bacterial respiratory diseases. Proceedings of the 15th International Pig Veterinary Society Congress, Birmingham, England, vol 1: 21-25.
Done SH and Paton DJ (1995). Porcine reproductive and respiratory syndrome: clinical disease, pathology and immunosuppression. Vet Ree, 136: 32-35
Done SH, Paton DJ, and White ME. (1996). Porcine reproductive and respiratory syndrome (PRRS): a review, with emphasis on pathological, virological and diagnostic aspects. Br Vet J, 152:153-174.
Done SH. (1997). Diseases and problems of swine respiratory - Respiratory epithelium. In: Proceedings of the 2nd International Meeting of Swine Medicine, Thessaloniki, 17 October 1997.
Aristotle University of Thessaloniki, Faculty of Veterinary Medicine, Department of Clinical Studies, Clinic of Productive Animal Medicine.
Done SH. (2001). Porcine Reproductive and Respiratory Syndrome: an update, with regard to vaccination. Pig Journal, 48: 159-175.
Done SH. (2003). Porcine Reproductive and Respiratory Syndrome (PRRS) Virus: an update. Pig Journal, 52: 206-233.
Dorr PM, Baker RB, Almond GW, Wayne SR, Gebreyes WA. (2007). Epidemiologic assessment of porcine circovirus type 2 coinfection with other pathogens in swine. J Am Vet Med Assoc 230(2): 244-50.
Drew TD, Lowings JP, Yapp F. (1997). Variation in open reading frames 3, 4 and 7 among porcine reproductive and respiratory syndrome virus isolates in the UK. Vet Microbiol, 55: 209-221.
Drew TW. (1999). Does PRRSV cause immunosuppresion? A review of the published evidence. In: Proceedings of PRRS and Aujeszky's disease Symposium, Ploufragan, France: 59-65.
Drew TW. (2000). A review of evidence for immunosuppression due to porcine reproductive and respiratory syndrome virus. Vet Res, 31: 27-39.
Drolet R, Thibault S, D' Allaire S, Thomson JR, Done SH. (1999). Porcine dermatitis and nephropathy syndrome (PDNS). Anoverview of the disease. J Swine Health Prod, 6: 283-285.
Fang Y, Kim DY, Ropp S, Steen P, Christopher-Hennings J, Nelson EA, Rowland RR. (2004). Heterogeneity in nsp2 of Europeanlike porcine reproductive and respiratory syndrome viruses
isolated in the United States. Virus Res, 100: 229-235.
Feng W-H, Laster SM, Tompkins M, Brown TT, Xu J-S, Altier C, Gomez W, Benfield D and McCaw MB. (2001). In utero infection by porcine reproductive and respiratory syndrome virus
is sufficient to increase susceptibility of piglets to challenge with Streptococcus suis type II. J Virol, 75: 4889-4895.
Forsberg R, Storgaard T, Nielsen HS, Oleksiewicz MB,Cordioli P, Sala G, Hein J, Botner Α. (2002). The genetic diversity of European type PRRSV is similar to that of the North American
type, but is geographically skewed within Europe. Virology, 20:38-47.
Fuentes M, Pijoan C. (1987) Pneumonia in pigs induced by intranasal challenge exposure with Pseudorabies virus and Pasteurella multocida. Am J Vet Res, 48: 1446-1448.
Galina L, Pijoan C, Sitjar M, Christianson WT, Rossow K, Collins JE. (1994). Interaction between Streptococcus suis serotype 2 and porcine reproductive and respiratory syndrome virus in specific
pathogen-free piglets. Vet Ree, 134: 60-64.
Galina L. (1995). Possible mechanism of viral-bacterial interaction in swine. J Swine Health Prod, 3(1): 9-14.
Georgakis AD, Bourtzi - Hatzopoulou E, Kritas SC, Balkamos GC, Kyriakis SC. (2002). Contribution in study of Porcine Respiratory Diseases Complex of Growing and Finishing Pigs (PRDC): New aspects and intended strategies for control. Journal of Hellenic Veterinary Association, 53 (3): 265-271.
Girard M, Cleroux P, Tremblay Ρ, Dea S and St Pierre Y. (2001). Increased proteolytic activity and matrix metalloprotease expression in lungs during infection by porcine reproductive and respiratory syndrome virus. J Gen Virol, 82: 1253-1261.
Gntanu G and Mandescu M. (2002). The economic effects of PRRSPRDC outbreak. In: Proceedings of the 17th International Pig Veterinary Society Congress, Ames, Iowa, USA, vol.2: 434.
Goldberg TL, Weigel RM, Hahn EC, Scherba G. (2000). Associations between genetics, farm characteristics and clinical disease in field outbreaks of porcine reproductive and respiratory
syndrome virus. Prev Vet Med, 43: 293-302.
Goldberg TL, Lowe JF, Milburn SM, Firkins LD. (2003). Quasispecies variation of porcine reproductive and respiratory syndrome virus during natural infection. Virology 317:193-207.
Grosse-Beilage E. (1995). Significance of PRRS virus infections for respiratory tract infections in swine: A literature review. Deutsche Tierarztliche Wochenschrift, 102: 457-469.
Halbur PG, Paul PS, Frey ML, Landgraf J, Ernissee K, Meng XJ, Lum MA, Andrews JJ and Rathje JA. (1995). Comparison of the pathogenicity of two U.S. porcine reproductive and respiratory syndrome virus isolates with that of the Lelystad virus. Pathol, 32: 648-660.
Halbur PG, Paul PS, Meng XJ, Lum MA, Andrews JJ and Rathje JA. (1996). Comparative pathogenicity of nine U.S. porcine reproductive and respiratory syndrome virus (PRRSV) isolates
in a five-week-old cesare-an-derived, colostrum-deprived pig model. J Vet Diagn Invest, 8: 11-20.
Halbur PG. (1998a). Porcine viral respiratory diseases. In: Proceedings of the 15th Pig Veterinary Society Congress, Birmingham, England, vol. 1: 1-9.
Halbur PG. (1998b). PRRSV interactions with Streptococcus suis and Mycoplasma hyopneumoniae. In: Proceedings of the 6th Annual Swine Disease Conference for Swine Practitioners, Ames, USA, Iowa State University, vol. 6: 9-14.
Halbur PG, Rothschild MF, Thacker BJ, Meng X-J, Paul PS, Bruna JD. (1998). Differences in susceptibility of Duroc, Hampshire and Meishan pigs to infection with a high virulence strain
(VR2385) of porcine reproductive and respiratory syndrome virus (PRRSV). J Anim Breed Genet, 115: 181-189.
Halbur PG, Thanawongnuwech R, Brown G. (2000). Efficacy of treatment and vaccination regimens for control of porcine reproductive and respiratory syndrome virus and Streptococcus
suis coinfection of nursery pigs. J Clin Microbiol, 38:1156-1160.
Hall MR, Williams PP, Rimler RB. (1987) A toxin from Pasteurella multocida serogroup D enhances swine herpesvirus 1 replication/lethality in vitro and in vivo. Curr Micro, 15: 277-281.
Harms PA, Sorden SD. (2000). Porcine circovirus associated pneumonia. In: MERIAL Proceedings of Post-weaning Multisystematic Wasting Syndrome Symposium, 16th International
Pig Veterinary Society Congress, Melbourne, Australia: 33-37.
Harms PA, Sorden SD, Halbur PG, Bolin SR, Lager KL, Morozov I, Paul PS. (2001). Experimental reproduction of severe disease in CD/CD pigs concurrently infected with type 2 porcinecircovirus and PRRSV. Vet Pathol, 38: 528-539.
Harms PA. (2002). Postweaning Multisystemic Wasting Syndrome and Porcine Circovirus. In: Trends in Emerging Viral Infections of Swine. Morula A, Yoon K-J, Zimmerman JJ (Eds), 1st ed.,
Iowa State Press.
Hoefling DC. (1990). Mystery disease. In: Proceedings of Ninetyfourth Annual Meeting of the United States Animal Health Association, Denver, Colorado, USA:. 501-504.
Iglesias JG, Trujano M, Xu J. (1992) Inoculation of pigs with Streptococcus suis type 2 alone or in combination with Pseudorabies virus. Am J Vet Res, 53: 364-367.
Indik S, Valicek L, Klein D, Klanova J. (2000). Variations in the major envelope glycoprotein GP5 of Chech strains of porcine reproductive and respiratory syndrome virus. J Gen Virol, 81:
-2502.
Indik S, Schmoll F, Sipos W, Klein D. (2005). Genetic variability of PRRS virus in Austria: consequences for molecular diagnostics and viral quantification. Vet Microbiol, 107: 171-179.
Johnson W, Roofa M, Vaughna E, Christopher-Hennings J, Johnson CR, Murtaugh MP. (2004). Pathogenic and humoral immune responses to porcine reproductive and respiratory syndrome
virus (PRRSV) are related to viral load in acute infection. Vet Immunol Immunopathol, 102: 233-247
Kapur Y, Elam MR, Pawlovich TM and Murtaugh MP. (1996). Genetic variation in porcine reproductive and respiratory syndrome virus isolates in midwestern United States. J Gen Virol, 77: 1271-1276.
Keffaber KK. (1989). Reproductive failure of unknown etiology. In: American Association of Swine Practitioners, Newsletter, 1:1-10.
Keffaber K, Stevenson G, Van Alstine W, Kanitz C, Harris I, Gorcyca D, Schlesinger Κ, Schultz R, Chladek D and Morrison R. (1992). SIRS virus infection in nursery/grower pigs. American
Association of Swine Practitioners, Newsletter, 4: 38-39.
Kennedy S, Moffett D, McNeilly E, Meehan B, Ellis J, Krakowka S and Allan GM. (2000). Reproduction of lesions of postweaning multisystemic wasting syndrome by experimental infection of conventional pigs with porcine circovirus type 2 alone or in combination with porcine parvovirus. J Comp Pathol, 122: 9-24.
Kubo M, Kimura K, Kobayashi M. et al. (1995). Pathological studies on natural and experimental porcine pneumonia caused by porcine reproductive and respiratory syndrome (PRRS) virus. Japan Agricultural Research Quarterly, 29: 201-205.
Kyriakis SC, Alexopoulos C, Paschaleri-Papadopoulou E, Tsinas AC, Kritas SK and Giannakopoulos C. (1996). Porcine Reproductive and Respiratory Syndrome (PRRS): present status of the disease and the Greek experience. In: Abstract Book of the Bilateral Veterinary Medical School Meeting: Belgrade-Thessaloniki, Kopaonic: 65-68.
Kyriakis SC, Alexopoulos C and Saoulidis K. (1997). Update for present status of porcine reproductive and respiratory syndrome (PRRS) in Greece. In: Proceedings of the 2nd International
Meeting of Swine Medicine, Thessaloniki, 17 October 1997.Aristotle University of Thessaloniki, Faculty of Veterinary Medicine, Department of Clinical Studies, Clinic of Productive Animal Medicine: 42-44.
Kyriakis SC, Kennedy S, Saoulidis K, Lekkas S, Miliotis ChC, Balkamos GC, Papoutsis PA. (2000). First report of the presence of post-weaning Multisystemic Wasting Syndrome and porcine
circovirus type 2 in Greece. In: Proceedings of the 16th International Pig Veterinary Society Congress, Melbourne, Australia: 633.
Lager KM, Mengeling WL, Wesley RD, Halbur PG, Sorden SD (1998). Acute PRRS. In: Proceedings of 29th Annual Meeting of American Association of Swine Practitioners, Des Moines, Iowa, USA: 449-453.
Lager KM, Mengeling WL, Brockmeier SL. (1999). Evaluation of protective immunity in gilts inoculated with the NADC-8 isolate of porcine reproductive and respiratory syndrome virus (PRRSV) and challenge-exposed with an antigenically distinct PRRSV isolate. Am J Vet Res, 60: 1022-1027.
Laval A. (1999). Respiratory diseases in swine. In: Proceedings of the Annual Meeting of Roche Vet Club, The Management of Respiratory Diseases in Swine Herds, Dinklage.
Lindhaus W and Lindhaus Β. (1991). Tatselhafte Sweinekrankheit. Praktische Tierarztl, 5: 423-425.
Loula T. (1991). Mystery pig disease. Agri-Practice, 12: 23-34.
Magar R, Larochelle R, Robinson Y and Dubuc C. (1993). Immunohistochemical detection of porcine reproductive and respiratory syndrome virus using colloidal gold. Can J Vet Res, 57: 300-304.
Mardassi N, Mounir S and Dea S. (1995). Structural gene analysis of a Quebec reference strain of porcine reproductive and respiratory syndrome virus (PRRSV). In: Corona and Related Viruses. Talbot PJ and Levy GA (Eds). New York: Plenum Press: 277-281.
Meier W, Wheeler J, Husmann, Osorio F, Zuckermann FA. (1999). Characteristics of the immune response of pigs to PRRS virus. In: Proceedings of the 3rd International Symposium on Porcine
Reproductive and Respiratory Syndrome (PRRS): 71-74.
Meng XJ, Paul PS, Halbur PG. (1994). Molecular cloning and nucleotide sequencing of the 30 terminal genomic RNA of porcine reproductive and respiratory syndrome virus. J Gen Virol, 75: 1795-1801.
Meng XJ, Paul PS, Halbur PG and Lum MA. (1995a). Phylogenetic analyses of the putative M (ORF 6) and Ν (ORF 7) genes of porcine reproductive and respiratory syndrome virus (PRRSV):
implication for the existence of two genotypes of PRRSV in the U.S.A. and Europe. Arch Virol, 140: 745-755.
Meng XJ, Paul PS, Halbur PG and Morozov I. (1995b). Sequence comparison of open reading frames 2 to 5 of low and high virulence United States isolates of porcine reproductive and respiratory syndrome virus. J Gen Virol, 76: 3181-3188.
Meng XJ, Paul PS, Halbur PG, Lum MA. (1996). Characterization of a high-virulence U.S. isolate of porcine reproductive and respiratory syndrome virus in a continuous cell line, ATCC CRL11171. J Vet Diagn Invest, 8: 374-381.
Meng XJ. (2000). Heterogeneity of porcine reproductive and respiratory syndrome virus: implications for current vaccine efficacy and future vaccine development. Vet Microbiol, 74:
-329.
Mengeling WL, Lager KM and Vorwald AC. (1994). Temporal characterization of transplacental infection of porcine fetuses with PRRS virus. Am J Vet Res, 55: 1391-1398.
Mengeling WL, Lager KM, Vorwald AC and Brockmeier SL. (1996). Comparison among strains of porcine reproductive and respiratory syndrome virus for their ability to cause reproductive
failure. Am J Vet Res, 57: 834-839.
Mengeling WL, Lager KM, Vorwald AC, Wesley RD and Clouser DF. (1997). An update of research at the National Animal Disease Centre on current strains of porcine reproductive and
respiratory syndrome (PRRS) virus. In: Proceedings of 24th Allen D. Leman Swine Conference, vol. 24: 138-145.
Mengeling WL, Lager KM, Vorwald AC. (1998). Clinical consequences of exposing pregnant gilts to strains of porcine reproductive and respiratory syndrome (PRRS) virus isolated from field cases of «atypical» PRRS. Am J Vet Res, 59: 1540-1544.
Mengeling WL, Lager KM, Vorwald AC. (1999). Safely and efficacy of vaccination of pregnant gilts against porcine reproductive and respiratory syndrome. Am J Vet Res, 60: 796-801.
Meredith M J. (1995). Porcine reproductive and respiratory syndrome (PRRS). In: Pig Disease Information Centre, Department of Clinical Veterinary Medicine, University of Cambridge, 1st
European Edition, August 1995, Boehringer Ingelheim: 5-10.
Meulenberg JJM, Hülst MM, de Meijer EJ, Moonen PL, den Besten A, de Kluyver EP, Wensvoort G, Moormann RJM. (1993). Lelystad virus, the causative agent of porcine epidemic abortion and respiratory syndrome (PEARS), is related to LDV and EAV. Virology, 192: 62-72.
Meulenberg J J, Hülst MM, de Meijer E J, Moonen PL, den Besten A, de Kluyver EP, Wensvoort G, Moormann RJ. (1994). Lelystad virus belongs to a new virus family, comprising lactate dehydrogenase-elevating virus, equine arteritis virus and simian hemorrhagic fever virus. Arch Virol Suppl, 9: 441-448.
Molitor TW, Xiao J and Choi CS. (1996). PRRS virus infection of macrophages: Regulation by maturation and activation state. In: Proceedings of the 27th Annual Meeting of American Association Swine Practitioners Nashville, Tennessee, USA:563-569.
Molitor TW, Bautista EM and Choi CS. (1997). Immunity to PRRSV: double-edged sword. Vet Microbiol, 55: 265-276.
Moore C. (1990). Clinical presentation of mystery swine disease in the growing pig. In: Proceedings of Mystery Swine Dis Comm Meet Livest Conserv Inst, Denver, Colo: 41-49.
Morrison RB, Collins JE, Harris L; Chladek DW, Gorcyca DE, Joo HS, Christiansen W, Benfield DA, Marsh WE, Goyal S and Annelli JF. (1992). Seroepidemiologic investigation of porcine epidemic abortion and respiratory syndrome (PEARS, PRRS, SIRS). In: Proceedings of the 12th International Pig Veterinary Society Congress, The Hague, The Netherlands, 12:114.
Mortensen S, Madsen K. (1992). The occurrence of PRRS in Denmark. American Association of Swine Practitioners, Newsletter, 4: 48.
Muirhead MR. (1992). Mystery disease, blue ear-Control program cuts losses dramatically. International Pigletter, 12: 9-11.
Murtaugh MP, Elam MR and Kakach LT. (1995). Comparison of the structural protein coding sequences of the VR-2332 and Lelystad virus strains of the PRRS virus. Arch Virol, 140: 1451-1460.
Murtaugh PM, Xiao Ζ and Zuckermann F. (2002). Immunological Responses of Swine to Porcine Reproductive and Respiratory Syndrome Virus Infection. Viral Immunology, 15 (4): 533-547.
Nelsen CJ, Murtaugh MP, Faaberg KS. (1999). Porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. J Virol, 73: 270-280.
Nelson EA, Christopher-Jennings J, Drew T, Wensvoort G, Collins JE Benfield DA. (1993). Differentiation of US and European isolates of porcine reproductive and respiratory syndrome virus by monoclonal antibodies. J Clin Microbiol 31: 3184-3189.
Neumann EJ, Kliebenstein JB, Johnson CD, Mabry JW, Bush E, Seitzinger AH, Green A, Zimmerman J J. (2005). Assessment of the economic impact of porcine reproductive and respiratory syndrome on swine production in the United States. J Am Vet Med Assoc, 227:385-392.
Ohlinger V, Weiland F, Weiland E, Mettenleiter Τ, Haas Β, Visser Ν, Ahi R. (1992). Some aspects of the virus causing PRRS in Germany. American Association of Swine Practitionners,
Newsletter, 4: 16.
Oleksiewicz MB, Botner A, Madsen KG, Storgaard T. (1998). Sensitive detection and typing of porcine reproductive and respiratory syndrome virus by RT-PCR amplification of whole viral genes. Vet Microbiol, 64: 7-22.
Oleksiewicz MB, Botner A, Toft P, Grubbe T, Nielsen J, Kamstrup S, Storgaard T. (2000). Emergence of porcine reproductive and respiratory syndrome virus deletion mutants: correlation with the porcine antibody response to a hypervariable site in the ORF 3 structural glycoprotein. Virology, 267: 135-140.
Osorio FA, Zuckermann F, Wills R, Meier W, Christian S, Galeota J, Doster A. (1998). PRRSV: comparison of commercial vaccines in their ability to induce protection against current PRRSV
strains of high virulence. In: Proceedings of the Allen D. Leman Swine Conference -1998, vol. 25: 176-182.
Papatsiros VG. (2006). Porcine Respiratory and Reproductive Syndrome (PRRS). A field study on the effect of long-term use of an inactivated vaccine on the health status of boars, sows and piglets. Doctoral Thesis. Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki.
Papatsiros VG, Alexopoulos C, Kritas SK, Koptopoulos G, Nauwynck H J, Pensaert MB and Kyriakis SC. (2006a). Longterm administration of a commercial porcine reproductive and respiratory syndrome virus (PRRSV)-inactivated vaccine in PRRSV-endemically infected sows. J Vet Med B, Infectious Diseases and Veterinary Public Health, 53: 266-272
Papatsiros V, Alexopoulos C, Kritas SK, Longo S, Joisel F, Kyriakis SC. (2006b). The effect of long-term vaccination of sows with a PRRSV inactivated vaccine on their health status and performance. In: Proceedings of 19th International Pig Veterinary Society, Copenhagen, Denmark, vol. 2: 47.
Papatsiros V, Alexopoulos C, Kritas SK, Longo S, Joisel F, Kyriakis SC. (2006c). The effect of long-term vaccination of sows with a PRRSV inactivated vaccine on their litter characteristics. In:
Proceedings of 19th International Pig Veterinary Society, Copenhagen, Denmark, vol. 2: 48.
Papatsiros V, Alexopoulos C, Kritas SK, Kyriakis SC. (2006c). Effect of the number of booster vaccinations of an inactivated PRRSV vaccine on sow health status. In: Proceedings of 19th International Pig Veterinary Society, Copenhagen, Denmark, vol. 2: 49.
Papatsiros V, Alexopoulos C, Kritas SK, Koptopoulos GS, Nauwynck H, Pensaert M, Kyriakis SC. (2006e). Serological profile at farm level after long-term vaccination of the breeding stock with a PRRSV inactivated vaccine. In: Proceedings of 19th International Pig Veterinary Society, Copenhagen, Denmark, vol. 2: 50.
Park BK, Yoon IJ, Joo HS. (1996). Pathogenesis of plaque variants of porcine reproductive and respiratory syndrome virus in pregnant sows. Am J Vet Res, 57: 320-323.
Pesch S, Meyer C, Ohlinger VF. (2005). New insights into the genetic diversity of European porcine reproductive and respiratory syndrome virus (PRRSV). Vet Microbiol, 107: 31-48.
Pesente P, Rebonato V, Sandri G, Giovanardi D, Lu Ruffoni LS, Torriani S. (2006). Phylogenetic analysis of ORF5 and ORF7 sequences of porcine reproductive and respiratory syndrome virus (PRRSV) from PRRS-positive Italian farms: A showcase for PRRSV epidemiology and its consequences on farm management. Vet Microbiol, 114: 214-224.
Pijoan C, Solano G, Segales J. (1994). PRRS virus and secondary disease. In: Proceedings of the 1994 Allen D. Leman Swine Conference, Minnesota, USA: 225-226.
Pol JM, van-Dijk JE, Wensvoort G and Terpstra C. (1991). Pathological, ultrastructural and immunohistochemical changes caused by Lelystad virus in experimentally induced infections of mystery swine disease (synonym: porcine epidemic abortion and respiratory syndrome (PEARS). Vet Q, 13: 137-143.
Pol J, van Leengoed I, Stockhofe Ν, and Wensvoort G. (1995). Dual infections of PRRS/influenza and PRRS/APP in the respiratory tract. In: Proceedings of the 2nd International Symposium Porcine Reproductive and Respiratory Syndrome, Copenhagen, Denmark: 22.
Pol J, Leengoed L, Stockhofe Kok G, Wensvoort G. (1997). Dual infections of PRRSV/infuenza or PRRSV/Actinobacillus pleuropneumoniae in the respiratory tract. Vet Microbiol, 55:259-264.
Poison DD, Marsh WE, Dial GD. (1990a). Financial evaluation and decision making in the swine breeding herd. Vet Clin Ν Am Food A, 8: 725-747.
Raymarkers JML. (1991). The experience of veterinary practice in Someren (Netherlands) with PEARS. European Comm Seminar on PRRS. 11/4-5, 1991. Brussels: 15.
Ropp SL,Wees CE, Fang Y, Nelson EA, Rossow KD, Bien, M, Arndt Β, Preszler S, Steen Ρ, Christopher-Hennings J, Collins JE, Benfield DA, Faaberg KS. (2004). Characterization of emerging European-like porcine reproductive and respiratory syndrome virus isolates in the United States. J Virol, 78: 3684-3703.
Rossow KD, Collins JE, Goyal SM, Nelson EA, Christopher- Hennings J and Benfield DA. (1995). Pathogenesis of porcine reproductive and respiratory syndrome virus infection in gnotobiotic pigs. Vet Pathol, 32: 361-373.
Rossow KD, Benfield DA, Goyal SM, Nelson EA, Christopher- Hennings J and Collins JE. (1996). Chronological immunohistochemical detection and localization of porcine reproductive
and respiratory syndrome virus infection in gnotobiotic pigs. Vet Pathol, 33: 551-556.
Saito A, Kanno T, Murakami Y, Muramatsu M and Yamaguchi S. (1996). Characteristics of major structural protein coding gene and leader-body sequence in subgenomic mRNA of porcine reproductive and respiratory syndrome virus isolated in Japan. J Vet Med Sci, 58: 377-380.
Saoulidis K, Kyriakis SC, Kennedy S, Lekkas S, Miliotis ChC, Allan G, Balkamos GC, Papoutsis PA. (2002). First report of postweaning multisystemic wasting syndrome and porcine dermatitis
and nephropathy syndrome in pigs in Greece. J Vet Med B, 49:202-205.
Scheldt AB, Cline TR, Clark IK. (1995). The effects of all in-all out growing-finishing on health of pigs. J Swine Health Prod, 3 (5):202-206.
Segales J, Piella J, Marco E, Mateu De Antonio EM, Espuna E and Domingo M. (1998). Porcine dermatitis and nephropathy syndrome in Spain. Vet Ree, 142: 483-486.
Segales J, Domingo M, Solano GI, Pijoan C. (1999). Porcine reproductive and respiratory virus and Haemophilus parasuis antigen distribution in dually infected pigs. Vet Microbiol, 64:287-297.
Snijder E J, van Toi H, Pedersen KW, Raamsman MJB, de Vries AAF. (1999). Identification of a novel structural protein of arteriviruses. J Virol, 73: 6335-6345.
Solano G, Segales J and Pijoan C. (1995). Interaction between porcine reproductive and respiratory syndrome virus (PRRSV) and Haemophilus parasuis. In: Proceedings of the 2nd International Symposium on Porcine Reproductive and Respiratory Syndrome, Copenhagen, Denmark: 21.
Sorden S. (2000). Diagnostic Notes: Update on porcine circovirus and postweaning multisystemic wasting syndrome. J Swine Health Prod, 8(3):133-136.
Stadejek T, Stankevicius A, Storgaard T, Oleksiewicz MB, Belak S, Drew TW, Pejsak Z. (2002). Identification of radically different variants of porcine reproductive and respiratory syndrome virus in Eastern Europe: towards a common ancestor for European and American viruses. J Gen Virol 83: 1861-1873.
Stevenson GW, Van Alstine WG, Kanitz CL and Keffaber KK. (1993). Endemic porcine reproductive and respiratory syndrome virus infection of nursery pigs in two swine herds without current reproductive failure. J Vet Diagn Invest, 5: 432-434.
Stevenson GW. (1998). Bacterial pneumonia in swine. In: Proceedings of the 15th International Pig Veterinary Society Congress, Birmingham, England, vol. 1: 11-20.
Suarez P, Zardoya R, Martin MJ, Prieto C, Dopazo J, Solana A and Castro JM. (1996). Phylogenetic relationships of European strains of porcine reproductive and respiratory syndrome virus (PRRSV) inferred from DNA sequences of putative ORF-5 and ORF-7 genes. Virus Res, 42: 159-165.
Sur J-H, Cooper VI, Galeota JA, Hesse RA, Doster AR and Osorio FA. (1996). In vivo detection of porcine reproductive and respiratory syndrome virus RNA by in situ hybridization at different times postinfection. J Clin Microbiol, 34: 2280-2286.
Sur JH, Doster AR, Christian JS, Galeota JA, Wills RW, Zimmerman JJ, Osorio FA. (1997). Porcine reproductive and respiratory syndrome virus replicates in testicular germ cells, alters spermatogenesis and induces germ cell death by apoptosis. J Virol, 71: 9170-9179.
Terpstra C, Wensvoort G and Pol JM. (1991). Experimental reproduction of porcine epidemic abortion and respiratory syndrome (mystery swine disease) by infection with Lelystad virus: Koch's postulates fulfilled. Vet Q, 13: 131-136.
Thacker E, Halbur P, Thucker B. (1998). Mycoplasma and PRRSV interactions-their possible roles in PRDC. In: Proceedings of 29th Annual Meeting of American Association of Swine Practitionners, Des Moines, Iowa: 351-354.
Thacker E, Halbur P, Ross RF. (1999). Mycoplasma hyopneumoniae potentiation of porcine reproductive and respiratory syndrome virus-induced pneumonia. J Clin Microbiol, 37: 620-627.
Thacker E. (1999) M. hyopneumoniae infections increase severity. Pig Progress, Respiratory Diseases (special edition): 8-10.
Thacker EL, Thacker BJ, Young TF, Halbur PG. (2000). Effect of vaccination on the potentiation of porcine reproductive and respiratory syndrome virus (PRRSV)-induced pneumonia by Mycoplasma hyopneumoniae. Vaccine, 18: 1244-1252.
Thanawongnuwech R, Thacker EL, Halbur PG. 1997. Effect of porcine reproductive and respiratory syndrome virus (PRRSV) (isolate VR-2385) infection on bactericidal activity of porcine pulmonary intravascular macrophages (PIMs): In vitro comparisons with pulmonary alveolar macrophages (PAMs). Vet Immunol Immunopathol, 59: 323-335.
Thanawongnuwech R, Halbur PG, Ackermann MR, Thacker EL, Royer RL. (1998a). Effects of low (modified-live virus vaccine) and high (VR-2385)-virulence strains of porcine reproductive
and respiratory syndrome virus (PRRSV) on pulmonary clearance of copper particles in pigs. Vet Pathol, 35: 398-406.
Thanawongnuwech R, Thacker EL, Halbur PG. (1998b). Influence of pig age on virus titer and bactericidal activity of porcine reproductive and respiratory syndrome virus (PRRSV)-infected
porcine intravascular macrophages (PIMs). Vet Microbiol, 63:177-187.
Thanawongnuwech R, Brown GB, Halbur PG. (2000). Pathogenesis of porcine reproductive and respiratory syndrome virus-induced increase in susceptibility in Streptococcus suis infection. Vet
Pathol, 37: 143-152.
Thanawongnuwech R, Amonsin A, Tatsanakit A, Damrongwatanapokin S. (2004). Genetics and geographical variation of porcine reproductive and respiratory syndrome virus (PRRSV) in Thailand. Vet Microbiol, 101: 9-21.
The European Agency for the evaluation of Medicinal Products, Veterinary Medicines Evaluation Unit, EMEA CVMP 595, 1998: VICH Topic GL9 (GCP) Step 4 Guideline on Good Clinical Practices, London UK: 1-28.
Thibault S, Drolet R, Germain MC, D' Allaire S, Larochelle R and Magar R. (1998). Cutaneous and systemic necrotizing vasculitis in swine. Vet Pathol, 35: 108-116.
Tzika E. (2002). Causes of death in weaning pigs on industrial pig farms in Greece. Doctoral Thesis. Faculty of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki.
Tzika ED, Kyriakis SC, Sarris K, Saoulidis K, Alexopoulos C, Batzios Ch. (2002). Causes of the postweaning mortality in industrial Greek swine units. In: Proceedings of the 17th International Pig Veterinary Society Congress, Ames, Iowa, USA, vol. 2: 284.
Van Alstine WG. (1991). Mystery swine disease in the United States. European Comm Seminar on PRRS. 11/29-30, 1991. Brussels:13.
Van Alstine W. (1992). Isolation of SIRS virus from nursery pigs of two herds without current reproductive failure. Proc Annu Meet Livest Conserv Inst, 1: 253-259.
Van Alstine WG, Stevenson GW and Kanitz CL. (1996). Porcine reproductive and respiratory syndrome virus does not exacerbate Mycoplasma hyopneumoniae infection in young pigs. Vet
Microbiol, 49: 297-303.
Van Reeth K, Koyen A, Pensaert M. (1994). Clinical effects of dual infections with porcine epidemic abortion and respiratory syndrome virus, porcine respiratory Coronavirus and swine
infuenza virus. In: Proceedings of the 13th International Pig Veterinary Congress, Bangkok, Thailand: 51.
Van Reeth K, Nauwynck H, Pensaert M. (1996). Dual infections offeeder pigs with porcine reproductive and respiratory syndrome virus followed by porcine respiratory Coronavirus or swine
infuenza virus: a clinical study and virological study. Vet Microbiol, 48: 325-335.
Van Reeth K, Labarque G, Nauwynck H, Pensaert M. (1999). Differential production of proinflammatory cytokines in the pig lung during different respiratory virus infections: correlations with pathogenicity. Res Vet Sci, 67: 47-52.
Vincent AL, Thacker BJ, Halbur PG, Rothschild MF, Thacker EL. (2005). In vitro susceptibility of macrophages to porcine reproductive and respiratory syndrome virus varies between genetically diverse lines of pigs. Viral Immunology, 18: 506-12
Voicu IL, Silim A, Morin M and Elazhary MASY (1994). Interaction of porcine reproductive and respiratory syndrome virus with swine monocytes. Vet Ree, 134:422-423.
Wensvoort G, Terpstra C, Pol JM, Ter Laak EA, Bloemraad M, De Kluyver EP, Kragten C, Van Buiten L, Den Besten A and Wagenaar F. (1991). Mystery swine disease in The Netherlands: the isolation of Lelystad virus. Vet Q, 13: 121-130.
Wensvoort G, De Kluyver EP, Luijtze EA, Den Besten A, Harris L, Collins JE, Christianson WT and Chaldek D. (1992). Antigenic comparison of Lelystad virus and swine infertility and respiratory syndrome (SIRS) virus. J Vet Diagn Invest, 4: 134-138.
Wensvoort G. (1993). Lelystad virus and the porcine epidemic abortion and respiratory syndrome. Vet Res, 24: 117-124.
White MEC. (1992). The clinical signs and symptoms of blue-eared pig disease (PRRS). Pig Vet J, 28: 62-68.
Wills RW, Gray JT, Fedorka-Cray PJ. (2000). Synergism between porcine reproductive and respiratory syndrome virus (PRRSV) and Salmonella choleraesuis in swine. Vet Microbiol, 71: 177-192.
Wootton S, Yoo D, Rogan D. (2000). Full-length sequence of a Canadian porcine reproductive and respiratory syndrome virus (PRRSV) isolate. Arch Virol, 145: 2297-2323.
Wu WH, Fang Y, Farwell R, Steffen-Bien M, Rowland RR, Christopher-Hennings J, Nelson EA. (2001). A 10-kDa structural protein of porcine reproductive and respiratory syndrome virus encoded by ORF2b. Virology, 287: 183-191.
Xilouri Frangiadaki E. (1993). First serological diagnosis of the Porcine Reproductive and Respiratory Syndrome in Greece. Journal of Hellenic Veterinary Association, 44 (1): 59-60.
Zeman D, Neiger R, Yaeger M, Nelson E, Benfield D, Leslie-Steen P, Thomson J, Miskimins D, Daly R and Minehart M. (1993). Laboratory investigation of PRRS virus infection in three swine
herds. J Vet Diagn Invest, 5: 522-528.
Zimmerman JJ, Johnson RA. (1991). A survey for «mystery swine disease» herds. 72nd Con Res Work Ani Dis. 11/11-12, Chicago: 306.
Zimmerman J J, Yoon K-J, Wills RW, Swenson SL. (1997). General overview of PRRS virus: A perspective from the United States. Vet Microbiol, 55: 187-196.
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